The polyphenylene oxides and methods for their preparation are known in the art. Various catalysts including manganese based catalysts have been employed for the preparation of these polymers by the oxidative coupling of phenolic monomers. These manganese catalyzed polymerizations are disclosed in McNelis, U.S. Pat. Nos. 3,220,979; Nakashio, 3,573,257 and Olander, 3,956,242. In the applicant's copending applications Ser. No. 491,475 filed, July 24, 1974, now U.S. Pat. No. 3,972,851, and Ser. No. 534,903 filed Dec. 20, 1974, now U.S. Pat. No. 3,965,069, there are disclosed novel procedures for polymerizing polyphenylene oxides with complex manganese based catalysts. Polyphenylene oxides are also described in Hay U.S. Pat. Nos. 3,306,874 and 3,306,875. All of these patents and applications are hereby incorporated by reference.
The processes employing manganese based catalysts have been based on the oxidative coupling of a phenolic monomer in an organic solvent. These processes are useful methods for preparing polyphenylene oxide resins, although the reaction rates have not been as rapid as would be desirable for commerical production of these resins. In copending application Ser. No. 582,910 various secondary amines are disclosed as being useful in the production of polyphenylene oxides in the presence of manganese catalysts. The particular reason for employing secondary amines is related to the production of a polyphenylene oxide which when combined with a styrene resin, will produce a composition having impact properties comparable to analogous compositions wherein the polyphenylene oxide is prepared with copper based catalyst systems. It has now been found that certain bis-secondary diamines within the scope of the disclosure of Ser. No. 582,910 may be employed to prepare more active catalyst systems that may be employed to achieve a shorter polymerization cycle wherein a polyphenylene oxide is produced that when combined with styrene resins result in a molding composition having good mechanical and impact properties. If desired the more active catalyst systems may be utilized on a material savings basis wherein reduced quantities of catalyst can be employed to oxidatively couple phenolic monomers at selected reaction rates.
Accordingly, it is a primary object of this invention to provide a method for enhancing the oxidative coupling rate of a phenolic monomer in the presence of a manganese chelate catalyst.
It is also a further object of this invention to provide a method for enhancing the oxidative coupling rate of a phenolic monomer in the presence of a manganese chelate catalyst which results in the production of a polyphenylene oxide resin that may be combined with styrene resins to produce molding compositions that have good mechanical and impact properties.